In a mail insertion machine, there is an envelope feeder on one end of the machine to sequentially release envelopes into an envelope inserting area. On the other end of the mail insertion machine, there is a gathering section where enclosure material is released and gathered. If the enclosure material contains a number of documents, the documents are separately released from a plurality of enclosure feeders. The released documents are then collated into a stack to be moved into the envelope inserting area where the document stack is inserted into the envelope. Envelopes can be fed from below the envelope inserting area by a lower envelope transport system. Usually, the flap of each envelope is flipped away from the throat of the envelope as the envelope is transported from the envelope feeder toward the envelope inserting area.
Mail insertion machines are well known. For example, U.S. Pat. No. 4,501,417 (Foster et al.) discloses an inserter feeder assembly for feeding enclosures; U.S. Pat. No. 4,753,429 (Irvine et al.) discloses a collating station; and U.S. Pat. No. 5,660,030 (Auerbach et al.) discloses an envelope inserting station wherein envelopes are separately provided to an envelope supporting deck where envelopes are spread open in order to allow enclosure material to be stuffed into the envelopes.
In a typical mail insertion machine, only one envelope is placed in the envelope inserting area at anytime to receive enclosure material. When the envelope is placed in the envelope inserting area and its flap is flipped away from the throat, the throat is spread open by a vacuum-suction device or by a set of mechanical fingers. As the envelope is fed from the envelope feeder from the upstream end of the inserting area, it is stopped by an envelope stopper so that the envelope is consistently placed at a desirable position for mail insertion. Typically, the vacuum-suction device or the mechanical fingers are fixedly located in the inserting area. Thus, the position of the envelope stopper must be adjusted in accordance with the length or size of the envelope.
It is desirable and advantageous to provide a method and an apparatus for adjusting the position of the envelope stopper according the size of the envelope in a simple yet precise manner.